1. Technological Field
The present invention relates to a biological information detector, a biological information measuring device, and method for designing a reflecting part in the biological information detector and the like.
2. Background Technology
A biological information measuring device measures human biological information such as, for example, pulse rate, blood oxygen saturation level, body temperature, or heart rate, and an example of a biological information measuring device is a pulse rate monitor for measuring the pulse rate. Also, a biological information measuring device such as a pulse rate monitor may be installed in a clock, a mobile phone, a pager, a PC, or another electrical device, or may be combined with the electrical device. The biological information measuring device has a biological information detector for detecting biological information, and the biological information detector includes a light-emitting part for emitting light towards a detection site (e.g., finger or arm) of a test subject (e.g., a user), and a light-receiving part for receiving light having biological information from the detection site.
There is disclosed in Japanese Laid-Open Publication No. 2004-337605 a reflection-type light sensor in which a light-emitting element and a light-receiving element are coaxially provided. The reflection-type light sensor described in Japanese Laid-Open Publication No. 2004-337605 is designed so that the detection sensitivity of the light-receiving element is at a maximum when a detection target (e.g., a finger) is positioned at a predetermined distance away from a window for transmitting light emitted from the light-emitting element. In paragraph [0032] in Japanese Laid-Open Publication No. 2004-337605, it is disclosed that the emission angle of the light-emitting element can be changed, the size of a substrate can be changed, and the curvature or focal point of a reflecting surface can be changed, in order to set a peak position at which the detection accuracy is at a maximum.